Active safety is one of the main focal points in the development of present as well as future motor vehicle systems. Known safety systems or driver-assistance systems in the area of the active safety of motor vehicle occupants, i.e. in order to avoid accidents involving the motor vehicle in question, are, for example, the electronic stability program (ESP) for stabilizing the motor vehicle by way of a braking intervention in the dynamic limit region, as well as vehicle dynamic management (VDM) as an extension of ESP using additional steering interventions. One known safety device of such a safety system is, for example, a lane change assistance system or evasion assistance system for the motor vehicle.
It is important to note, when designing such safety devices and the safety systems at a higher order above them, that average motor vehicle drivers often have problems in dangerous situations evading an obstacle by suitable steering maneuvers. It is found in driver training sessions, for example, that steering input by the average motor vehicle driver occurs too late, too quickly or slowly, too much or too little, or not at all, and moreover that a countersteering action, e.g. in the context of a double lane change (i.e. back to the original lane) is performed incorrectly or not at all. This leads either to a collision with an obstacle or to instabilities, and in serious cases causes the motor vehicle to skid. A plurality of driver assistance systems (DAS) or advanced driver assistance systems (ADAS) therefore exist as additional electronic or mechatronic devices in motor vehicles to assist the vehicle driver in critical driving situations.
EP 970 875 A2 teaches a safety system for motor vehicles with which, based on data from distance sensors, a steering actuation suite of a steer-by-wire system of a motor vehicle can be influenced in such a way that a motor vehicle driver can at least be prevented from establishing a steering angle that leads to a collision. The safety system can, in this context, optionally automatically establish an evasion course. With this safety system, a decision as to whether, when, and in what direction evasion occurs is made by the safety system and taken away from the motor vehicle driver. No determination of an evasion trajectory occurs, however, except for a defined steering angle for the evasion course.
EP 1 735 187 B2 discloses a safety system for motor vehicles having a steering device and a braking device, a risk of collision with an obstacle in front of the motor vehicle being sensed and evaluated by the safety system for evasion assistance in emergency situations of the motor vehicle. This is accomplished on the basis of internal information about the motor vehicle and external information based on sensors, etc. If a risk of a collision by the motor vehicle is high, a steering assistance action by the safety system is initiated as soon as the vehicle driver begins an evasive maneuver or an excessively tentative evasive maneuver. For this, an evasion trajectory is calculated and is conveyed to the vehicle driver in the form of a steering torque, a haptic signal, or an exertable additional steering angle. The evasion trajectory specified by the safety system can be overridden by the motor vehicle driver. A criterion or optimization criteria for the evasion trajectory is not disclosed.